21908844 has 36 divisors (see below), whose sum is σ = 56672616. Its totient is φ = 7132608.

The previous prime is 21908839. The next prime is 21908849. The reversal of 21908844 is 44880912.

It is an interprime number because it is at equal distance from previous prime (21908839) and next prime (21908849).

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21908799 and 21908808.

It is not an unprimeable number, because it can be changed into a prime (21908849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5529 + ... + 8624.

Almost surely, 2^21908844 is an apocalyptic number.

It is an amenable number.

21908844 is an abundant number, since it is smaller than the sum of its proper divisors (34763772).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21908844 is a wasteful number, since it uses less digits than its factorization.

21908844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14206 (or 14201 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 21908844 is about 4680.6884109071. The cubic root of 21908844 is about 279.8163932337.

The spelling of 21908844 in words is "twenty-one million, nine hundred eight thousand, eight hundred forty-four".